EP0369045B1 - Process for the production of ceramic green sheets - Google Patents
Process for the production of ceramic green sheets Download PDFInfo
- Publication number
- EP0369045B1 EP0369045B1 EP88119004A EP88119004A EP0369045B1 EP 0369045 B1 EP0369045 B1 EP 0369045B1 EP 88119004 A EP88119004 A EP 88119004A EP 88119004 A EP88119004 A EP 88119004A EP 0369045 B1 EP0369045 B1 EP 0369045B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- formula
- weight
- radicals
- oxide units
- ceramic green
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 238000000034 method Methods 0.000 title claims description 9
- 230000008569 process Effects 0.000 title claims description 7
- 239000002270 dispersing agent Substances 0.000 claims abstract description 70
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 claims abstract description 37
- 239000004014 plasticizer Substances 0.000 claims abstract description 26
- 238000005266 casting Methods 0.000 claims abstract description 22
- 239000000758 substrate Substances 0.000 claims abstract description 22
- 150000001875 compounds Chemical class 0.000 claims abstract description 17
- 239000001023 inorganic pigment Substances 0.000 claims abstract description 17
- 238000001035 drying Methods 0.000 claims abstract description 13
- 239000003960 organic solvent Substances 0.000 claims abstract description 9
- 125000005702 oxyalkylene group Chemical group 0.000 claims abstract description 9
- 238000009826 distribution Methods 0.000 claims abstract description 6
- 238000005245 sintering Methods 0.000 claims abstract description 5
- 238000010438 heat treatment Methods 0.000 claims abstract description 4
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical group CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 claims description 12
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical group C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 claims description 11
- 229920001400 block copolymer Polymers 0.000 claims description 10
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 10
- 125000001931 aliphatic group Chemical group 0.000 claims description 9
- 239000010954 inorganic particle Substances 0.000 claims description 9
- 229920000768 polyamine Polymers 0.000 claims description 7
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical group OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 claims description 6
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 claims description 4
- 125000003277 amino group Chemical group 0.000 claims description 4
- 150000003141 primary amines Chemical class 0.000 claims description 3
- 150000003335 secondary amines Chemical class 0.000 claims description 3
- 150000001412 amines Chemical class 0.000 claims description 2
- 125000004433 nitrogen atom Chemical class N* 0.000 claims description 2
- 125000001424 substituent group Chemical group 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 claims 1
- 239000011230 binding agent Substances 0.000 description 27
- 239000011521 glass Substances 0.000 description 16
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 15
- 238000012360 testing method Methods 0.000 description 15
- 230000000694 effects Effects 0.000 description 14
- 239000000049 pigment Substances 0.000 description 13
- 239000000654 additive Substances 0.000 description 11
- 239000002245 particle Substances 0.000 description 9
- 239000000203 mixture Substances 0.000 description 8
- 238000010998 test method Methods 0.000 description 8
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- 235000021323 fish oil Nutrition 0.000 description 7
- 125000000963 oxybis(methylene) group Chemical group [H]C([H])(*)OC([H])([H])* 0.000 description 7
- 239000002002 slurry Substances 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- XSTXAVWGXDQKEL-UHFFFAOYSA-N Trichloroethylene Chemical group ClC=C(Cl)Cl XSTXAVWGXDQKEL-UHFFFAOYSA-N 0.000 description 6
- 230000009471 action Effects 0.000 description 6
- -1 phthalic acid ester Chemical class 0.000 description 6
- DOIRQSBPFJWKBE-UHFFFAOYSA-N dibutyl phthalate Chemical group CCCCOC(=O)C1=CC=CC=C1C(=O)OCCCC DOIRQSBPFJWKBE-UHFFFAOYSA-N 0.000 description 5
- 239000011888 foil Substances 0.000 description 5
- 239000012071 phase Substances 0.000 description 5
- 241000273930 Brevoortia tyrannus Species 0.000 description 4
- MQIUGAXCHLFZKX-UHFFFAOYSA-N Di-n-octyl phthalate Natural products CCCCCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCCCC MQIUGAXCHLFZKX-UHFFFAOYSA-N 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 150000002148 esters Chemical class 0.000 description 4
- 239000006260 foam Substances 0.000 description 4
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- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
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- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- XNGIFLGASWRNHJ-UHFFFAOYSA-N o-dicarboxybenzene Natural products OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 3
- 239000011164 primary particle Substances 0.000 description 3
- IRIAEXORFWYRCZ-UHFFFAOYSA-N Butylbenzyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCC1=CC=CC=C1 IRIAEXORFWYRCZ-UHFFFAOYSA-N 0.000 description 2
- SNRUBQQJIBEYMU-UHFFFAOYSA-N Dodecane Natural products CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- 239000002518 antifoaming agent Substances 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 150000002894 organic compounds Chemical class 0.000 description 2
- 239000012074 organic phase Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- CXMXRPHRNRROMY-UHFFFAOYSA-N sebacic acid Chemical compound OC(=O)CCCCCCCCC(O)=O CXMXRPHRNRROMY-UHFFFAOYSA-N 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000007669 thermal treatment Methods 0.000 description 2
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 description 2
- 238000001238 wet grinding Methods 0.000 description 2
- QGLWBTPVKHMVHM-KTKRTIGZSA-N (z)-octadec-9-en-1-amine Chemical compound CCCCCCCC\C=C/CCCCCCCCN QGLWBTPVKHMVHM-KTKRTIGZSA-N 0.000 description 1
- ITRHZTGVVSWIDC-UHFFFAOYSA-N 11-methyl-1-(11-methyldodecoxy)dodecane Chemical compound CC(C)CCCCCCCCCCOCCCCCCCCCCC(C)C ITRHZTGVVSWIDC-UHFFFAOYSA-N 0.000 description 1
- VILCJCGEZXAXTO-UHFFFAOYSA-N 2,2,2-tetramine Chemical compound NCCNCCNCCN VILCJCGEZXAXTO-UHFFFAOYSA-N 0.000 description 1
- CBECDWUDYQOTSW-UHFFFAOYSA-N 2-ethylbut-3-enal Chemical group CCC(C=C)C=O CBECDWUDYQOTSW-UHFFFAOYSA-N 0.000 description 1
- CCTFMNIEFHGTDU-UHFFFAOYSA-N 3-methoxypropyl acetate Chemical compound COCCCOC(C)=O CCTFMNIEFHGTDU-UHFFFAOYSA-N 0.000 description 1
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 1
- 206010013786 Dry skin Diseases 0.000 description 1
- 229920005682 EO-PO block copolymer Polymers 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- 239000006057 Non-nutritive feed additive Substances 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000001361 adipic acid Substances 0.000 description 1
- 235000011037 adipic acid Nutrition 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- 230000003254 anti-foaming effect Effects 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- ZFMQKOWCDKKBIF-UHFFFAOYSA-N bis(3,5-difluorophenyl)phosphane Chemical compound FC1=CC(F)=CC(PC=2C=C(F)C=C(F)C=2)=C1 ZFMQKOWCDKKBIF-UHFFFAOYSA-N 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 150000001991 dicarboxylic acids Chemical class 0.000 description 1
- HPNMFZURTQLUMO-UHFFFAOYSA-N diethylamine Chemical compound CCNCC HPNMFZURTQLUMO-UHFFFAOYSA-N 0.000 description 1
- 125000003438 dodecyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 238000009837 dry grinding Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- NAQMVNRVTILPCV-UHFFFAOYSA-N hexane-1,6-diamine Chemical compound NCCCCCCN NAQMVNRVTILPCV-UHFFFAOYSA-N 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002763 monocarboxylic acids Chemical class 0.000 description 1
- SZEGKVHRCLBFKJ-UHFFFAOYSA-N n-methyloctadecan-1-amine Chemical compound CCCCCCCCCCCCCCCCCCNC SZEGKVHRCLBFKJ-UHFFFAOYSA-N 0.000 description 1
- 125000002347 octyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000006353 oxyethylene group Chemical group 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- KCXZNSGUUQJJTR-UHFFFAOYSA-N phthalic acid dihexyl ester Natural products CCCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCC KCXZNSGUUQJJTR-UHFFFAOYSA-N 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 229920005604 random copolymer Polymers 0.000 description 1
- 125000000467 secondary amino group Chemical group [H]N([*:1])[*:2] 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 125000004079 stearyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 229920001897 terpolymer Polymers 0.000 description 1
- 235000021122 unsaturated fatty acids Nutrition 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/632—Organic additives
- C04B35/634—Polymers
- C04B35/63404—Polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C04B35/6342—Polyvinylacetals, e.g. polyvinylbutyral [PVB]
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/632—Organic additives
- C04B35/634—Polymers
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/632—Organic additives
- C04B35/634—Polymers
- C04B35/63448—Polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- C04B35/63488—Polyethers, e.g. alkylphenol polyglycolether, polyethylene glycol [PEG], polyethylene oxide [PEO]
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K23/00—Use of substances as emulsifying, wetting, dispersing, or foam-producing agents
- C09K23/42—Ethers, e.g. polyglycol ethers of alcohols or phenols
- C09K23/46—Ethers of aminoalcohols
Definitions
- the invention relates to the production of ceramic green films by casting and drying a slip which contains finely divided inorganic pigment, organic solvents, polyvinyl butyral, plasticizers and dispersants, ceramic green films having surprisingly advantageous properties which can be obtained by the following being obtained using special dispersants according to the invention Have thermal treatment converted into isotropic ceramic substrates.
- Substrates made of ceramic materials can be produced by casting so-called slip.
- Slurry is understood to mean a slurry of inorganic pigments in an organic solvent which contains a polymeric binder such as polyvinyl butyral and a plasticizer such as e.g. contains a phthalic acid ester.
- This slip is poured onto a continuously running metal or plastic belt, a constant layer thickness of the casting compound being set by means of a doctor blade.
- the slip is dried on the belt and a flexible green film is formed, which can be continuously removed from the belt.
- the green film can easily be processed further by cutting and punching.
- the organic components are then evaporated from the film using a special temperature program and finally sintered to the substrate at high temperatures.
- the green film tends to stick to the tape, especially on metal tape. To pull off the tape so much force is required that the film is stretched. It is known to treat the tape with a lubricant, which lowers the adhesion of the film, though often not sufficiently.
- non-spherical inorganic particles for example commercially available aluminum oxide, are oriented in the direction of flow. This orientation is reinforced if the organic solvent / binder / plasticizer system as such is not homogeneous, but rather multi-phase and if the particle size distribution of the inorganic pigments is large.
- the invention therefore relates to a process for the production of ceramic green sheets by casting and drying a slip which contains finely divided inorganic pigment, organic solvents, polyvinyl butyral, plasticizers and dispersants, characterized in that compounds are used as dispersants which have at least one in their molecules Structural unit of formula Z, ⁇ N- (A) x - (B) y H (Z) wherein A and B, which must be different, are either the oxyalkylene unit -C3 ⁇ 4H6 ⁇ 8O- or the oxyalkylene unit -C2H4O- and x and y, which may be the same or different, each have a number from 1 to 200, preferably 2 to 50, mean contain.
- One embodiment of the invention consists in that the structural unit of the formula Z has the formulas Z 1 or Z 2, ⁇ N- (C2H4O) x - (C3H6O) y H (Z1) ⁇ N- (C3H6O) x - (C2H4O) y H (Z2) where x and y each have the meanings as in formula Z, corresponds.
- groups A and B therein represent the oxyalkylene units -C3H6O- or -C2H4O-, where A and B are not the same, ie groups A and B in formula Z together always form block-copolymer structures or represent block-copolymer adducts.
- a preferred embodiment of the invention consists in that the dispersant according to the invention has the formulas I and / or II, where x and y each have the meanings as in formula Z, corresponds.
- the invention further relates to ceramic green sheets, produced by casting and drying a slip which contains finely divided inorganic pigment, organic solvents, polyvinyl butyral, plasticizers and, as dispersants, compounds which contain at least one structural unit of the formula Z in their molecules.
- the invention further relates to a ceramic substrate, produced from ceramic green foils obtained according to the invention by thermal treatment and sintering, preferably by heating and sintering at temperatures of at least 1600 ° C., it being composed of isotropically distributed inorganic particles.
- a further embodiment of the invention is that the dispersant according to the invention contains compounds which, by adding one or more block copolymer structured residues of x ethylene oxide and y propylene oxide units or x propylene oxide and y ethylene oxide units, where x and y in the Block copolymer structured radicals have the meanings as in formula Z, to the amino groups of primary or secondary amines, preferably aliphatic amines, with amino-N atoms substituted by aliphatic (C1-C18) radicals, or of primary or primary / secondary or secondary di- or polyamines, preferably aliphatic di- or polyamines with amino-N atoms substituted by aliphatic (C1-C18) radicals or amino-N-atoms linked to one another by multi-bonded aliphatic (C1-C12) radicals, in particular di- or polyamines with 2 to 4 primary and / or secondary amino groups, the amines or diodes mentioned r Polyamines can also contain ter
- a preferred embodiment of the invention further consists in the fact that the dispersant according to the invention contains compounds which, by adding four block copolymer structured residues of x ethylene oxide and y propylene oxide units or x propylene oxide and y ethylene oxide units, where x and y are in the block copolymer structured radicals have the meanings as in formula Z, on which amino groups of ethylenediamine can be represented.
- the dispersants of the invention have a good to excellent dispersing action.
- the inorganic particles dispersed according to the invention are present in the slip as primary particles, which do not aggregate prematurely even when the slip dries and which are not or only slightly oriented during casting, so that isotropic green films with optimum density and thus optimal packing density of the inorganic particles are obtained.
- the compounds according to the invention are compatible with polyvinyl butyral and the customary solvents and plasticizers, so that the pigment-free organic phase results in completely clear films.
- dispersants according to the invention reduce the adhesion of the green films to the casting belt, so that no warping or stretching occurs when the films are removed.
- the dispersants to be used according to the invention are in particular known compounds with one or more of the structural units ⁇ N- (C2H4O) x - (C3H6O) y H and ⁇ N- (C3H6O) x -) C2H4O) y H, where x and y each have the meanings as in formula Z.
- all block-like or block-copolymeric adducts of propylene oxide and ethylene oxide with any primary and / or secondary amines are suitable.
- the adducts with primary and secondary aliphatic mono-, di- and polyamines such as e.g. Ethyl, butyl, octyl, dodecyl, stearyl and oleylamine, diethylamine, methylstearylamine, ethylenediamine, 1,6-hexylenediamine, diethylenetriamine and triethylenetetramine.
- adducts of ethylenediamine of the formula Z3 are particularly preferred, where A, B, x and y have the meanings as in formula Z.
- the concentration of the compounds to be used according to the invention can vary within wide limits. In principle, it is desirable to use as little dispersant as possible so as not to impede the pouring and drying of the slip. On the other hand, it is necessary to completely and optimally disperse the inorganic particles, which in turn depends on their type and size or their surface. The same applies to the necessary lowering of the adhesion of the green film on the casting belt. Finally, as mentioned, attention must also be paid to the compatibility of the entire binder system will. However, the person skilled in the art can determine the optimum concentration of dispersant using the rules mentioned and the test methods described below.
- the dispersants or dispersant mixtures according to the invention are used in concentrations between 0.1 and 10% by weight, based on the inorganic pigment.
- a preferred range is between 0.2 and 5% by weight.
- Concentrations between 0.4 and 3% by weight are particularly preferred.
- the commercially available polyvinyl butyrals can be used as binders. These polyvinyl butyrals have viscosities, measured on their 5% strength by weight solutions in ethanol at 23 ° C., between 3 and 100 mPa ⁇ s. Polyvinyl butyrals or else polyvinyl butyral mixtures with viscosities between 5 and 20 mPa ⁇ s are particularly suitable.
- the commercially available polyvinyl butyrals are terpolymers which, in addition to vinyl butyral units, contain about 0.5 to 3% by weight of vinyl acetate and 12 to 28% by weight of vinyl alcohol units.
- the vinyl alcohol units in particular have a significant influence on the solubility, the mechanical and the rheological properties of the polyvinyl butyrals.
- the compatibility with plasticizer and dispersant on the one hand and the mechanical properties on the other hand are of particular importance.
- polyvinyl butyrals with a vinyl alcohol unit content of between 15 and 22% by weight are particularly preferred.
- the concentration of binder has a significant influence on the strength and processability of the green sheets. Films with too little binder are not very strong and are brittle, too much binder makes it difficult to heat the organic constituents out of the green film and can lead to cracking in the substrate.
- polyvinyl butyral concentrations between 2 and 10 wt .-%, based on the inorganic pigments used. A preferred range is 3 to 6% by weight.
- plasticizer-free green films are not flexible enough and are brittle.
- the plasticizer / binder ratio determines the flexibility of the film. Increasing plasticizer concentrations improve the stretchability of the film, with decreasing plasticizer content the strength increases. However, the prerequisite is that it is a homogeneous, i.e. single-phase plasticizer / binder system. In principle, all plasticizers are suitable that meet this requirement, i.e. which are compatible with polyvinyl butyral.
- esters of dicarboxylic acids such as phthalic acid, adipic acid and sebacic acid
- aliphatic or aliphatic-aromatic alcohols such as dibutyl, dihexyl or dioctyl phthalate, butylbenzyl phthalate, dioctyl adipate or dibutyl sebazate, and, if appropriate, the corresponding esters of phosphoric acid are particularly suitable.
- Esters of monocarboxylic acids with polyhydric alcohols such as e.g. the esters of triethylene glycol with aliphatic monocarboxylic acids having 6 to 8 carbon atoms.
- ethers of long-chain alcohols are suitable, such as the mono-isotridecyl ether of triethylene glycol.
- the dispersants to be used according to the invention also act in principle as plasticizers, which are suitable for increasing the flexibility of the green films. For this reason, the dispersant can at least partially replace the non-dispersing plasticizers mentioned above.
- the concentration of non-dispersing plasticizer is therefore between 0 and 200 wt .-% based on the Polyvinylbutyral used.
- a preferred range is between 10 and 150% by weight, the upper limit of the plasticizer concentration being set by the incompatibility that is beginning.
- the usual solvents are used to produce the slip. These are in particular alcohols such as methanol and ethanol, halogenated hydrocarbons such as trichlorethylene, ketones such as methyl ethyl ketone or methyl isobutyl ketone, aromatic hydrocarbons such as toluene or xylene. Mixtures of these solvents are also frequently used.
- the solvent primarily affects the viscosity of the slip and the drying speed of the green sheet.
- concentration of the solvent is not critical and is within the usual limits, preferably between 20 and 100 parts by weight of solvent, in particular 30 to 50 parts by weight, per 100 parts by weight of inorganic pigment.
- all pigments which are suitable for the casting process can be used in the process according to the invention. They can be manufactured or processed in any way for the intended use according to the invention, e.g. by dry or wet grinding. For the preparation of an easily dispersible inorganic pigment, however, it can be advantageous if, e.g. after wet grinding, the pigment is dried in the presence of a dispersant to be used according to the invention.
- inorganic pigment powders are suitable, such as, for example, the oxides of aluminum, magnesium and silicon, barium titanate, silicon, silicon carbide, quartz, aluminosilicates, mixtures of such products and others. They are particularly suitable Dispersant to be used according to the invention in the production of substrates based on aluminum oxide.
- the slip can also contain other additives, such as leveling agents and stabilizers, which, like the other organic compounds contained in the slip, should be compatible with the binder system.
- additives such as leveling agents and stabilizers, which, like the other organic compounds contained in the slip, should be compatible with the binder system.
- organic processing aids which are incompatible with the organic phase and which are embedded in the green film in a finely divided and inert manner.
- Such additives e.g. so-called liquefiers such as fish oil or other fatty acid esters can facilitate the liquefaction of the slip during manufacture. However, they must not disturb the continuity of the binder phase and must not impair the dispersing action of the compounds according to the invention. Their concentration, based on the pigment used, should therefore not exceed 2% by weight, preferably 1% by weight.
- the slips are prepared and processed by customary methods, for example by grinding the pigment which has been pretreated in the customary manner and, if appropriate, comminuted in organic solvents, it being possible for binders, plasticizers, dispersants and other additives to be added in any order. However, it is preferable to add the dispersant and, if appropriate, the liquefier early, and to add the binder relatively late.
- the finished slip is applied with the help of a casting shoe and a doctor blade to a continuously running belt, dried and drawn off.
- the green film can then be processed further in the usual way.
- the aluminum oxide green film can be used to produce conductor tracks, insulators, carriers for silicon chips, carriers for electronic circuits, etc.
- the organic components are knife-coated onto the clean glass plate in the composition intended for slip production with a 0.2 mm wet film thickness. After a drying time of at least 24 hours at room temperature, the film is viewed under a microscope at approx. 200-fold magnification with lateral light. In the absence of the inert additives mentioned above as liquefiers, no separation of a second phase must be recognizable. If the film is folded into a loop and stored at 23 ° C at 100% relative humidity for 3 days, no separation should be discernible on the inside of the loop.
- the dispersing power of a dispersing agent is also determined in the organic solution that is to be used for the slip production - but in the absence of the binder.
- organic solution 0.1 part by weight of pigment with an average particle size of approximately 0.5 ⁇ m and a narrow particle size distribution (for example Kronos titanium dioxide RN 56) in 10 parts by weight of solution in the presence of glass beads are shaken vigorously for 3 hours.
- the dispersing effect is satisfactory if the pigment only partially settles after standing for 20 hours; it is good if it is in has only deposited a small amount of the pigment during this time. If a diluted pigment slurry is viewed under the microscope after it has been produced in the manner described, no or only a few pigment aggregates must be recognizable.
- a good dispersing effect can also be found indirectly in the production of the substrates. If two green films contain the same inorganic components and the same amount of different binder systems, the film with better dispersion has a higher density and less shrinkage when sintered to the substrate than the film with less well-dispersed inorganic particles.
- a film is knife-coated onto a clean glass plate (slide) and dried for 24 hours.
- Adhesion is "very low” if the film can be removed with tweezers from a slide with a dimension of approx. 25x76x1 mm and with its back lying loosely on a surface without having to touch the slide.
- the liability is "low” if a 6 cm wide film can be pulled off from a glass plate with the dimensions 100x300x3 mm in a corresponding manner.
- Adhesion is "moderate” if the glass plate has to be touched when pulling it off, but the film is not stretched too much.
- the liability is “high” if the film is stretched and “very high” if the film cannot be removed undamaged.
- a green film with a wet film thickness of 200 ⁇ m is knife-coated onto a clean glass plate, it can be "easily” removed after drying if this can be done effortlessly without the film tearing at any point.
- the viscosity measurement of the slip or of the organic solutions can be carried out using conventional viscometers from the Höppler system or the Brookfield system.
- the tensile strength and tensile elongation of pigment-free films and green films can also be checked using commercially available machines.
- An Instron machine was used to check the green sheets.
- Film strips with a thickness of 0.5 to 0.8 mm and a width of 15 mm were torn at a clamping length of 50 mm at a speed of 5 mm / min.
- orientation can be recognized macroscopically or microscopically by streaking, alignment of the pigments or formation of structures aligned in the casting direction. A corresponding examination is not meaningful for green foils. The orientation of these foils can best be seen from the different shrinkage along and across the casting direction when the green foil is fired and sintered to the substrate.
- the tendency to foam in the organic binder system can best be determined in the absence of inorganic pigments. A sample is shaken in a defined manner and the collapse of the foam formed on the surface is observed in comparison to a standard sample.
- a solution was prepared from 10 parts by weight of polyvinyl butyral, 61.5 parts by weight of trichlorethylene, 25 parts by weight of anhydrous ethanol and 3.5 parts by weight of bis-2-ethylhexyl phthalate (DOP).
- Example 1 was repeated with the modification that instead of the dispersants a) or b) according to the invention, the customary additives given in Table 1a) were used. The tests were carried out analogously to Example 1. The test results are shown in Table 1a) below.
- Example 1 shows that the dispersants according to the invention are compatible with polyvinyl butyral and plasticizers and cause little foaming, while the known additives according to Comparative Example 1 lead to disadvantages.
- Example 2 was repeated with the modification that instead of the dispersants a) or b) according to the invention, those given in Table 2a) and to influence the Dispersion customary additives were used.
- the tests were carried out analogously to Example 2. The test results are shown in Table 2a) below.
- Example 2 shows that the dispersants of the invention, compared to conventional dispersants based on ethylene oxide or propylene oxide adducts from Comparative Example 2, have a superior dispersing action.
- a solution was prepared from 10 parts by weight of polyvinyl butyral, 60.5 parts by weight of trichlorethylene, 24.5 parts by weight of anhydrous ethanol, 1.0 part by weight of methoxypropyl acetate and 4.0 parts by weight of dibutyl phthalate.
- the polyvinyl butyral used had a proportion of 19.2% by weight of vinyl alcohol units and a viscosity of 9.5 mPa ⁇ s, measured in a 5% by weight solution in ethanol at 23 ° C.
- Example 3 was repeated with the modification that, instead of the dispersants a) or b) according to the invention, the additives given in Table 3a) and customary for influencing the dispersion were used.
- the tests were carried out analogously to Example 3. The test results are shown in Table 3a) below.
- Example 3 demonstrates the adhesion-reducing effect of dispersants according to the invention compared to comparison substances of comparative example 3 which are usually used as dispersants.
- the solution was knife-coated onto a glass plate with a wet film thickness of 200 ⁇ m. The dried film adhered very strongly to the glass plate.
- Two polymer solutions were each prepared from polyvinyl butyral, trichlorethylene, ethanol and dioctyl phthalate as described in Example 1.
- the film had a tear strength of 2.1 N / mm2 and an elongation at break of 10.5%. If Menhaden fish oil was used in this formulation instead of the dispersant b) of the formula II according to the invention, the resulting film was very difficult to remove from the glass. With a tensile strength of 2.1 N / mm2, it also had an elongation at break of only 7.6%.
- a substrate was produced from the green sheet by firing at 1600 ° C. The shrinkage that occurred was 17.1% in the longitudinal direction and 17.0% in the transverse direction.
- the adhesive adhered the resulting film is much stronger on the casting belt.
- the shrinkage when burning to the substrate was 19.2% (lengthways) and 18.1% (lengthways).
- the lower, more uniform and largely isotropic shrinkage of the film produced by the process according to the invention demonstrates the better dispersion compared to the comparative test according to the prior art.
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Abstract
Description
Die Erfindung betrifft die Herstellung von keramischen Grünfolien durch Vergießen und Trocknen eines Schlickers, der feinteiliges anorganisches Pigment, organische Lösungsmittel, Polyvinylbutyral, Weichmacher und Dispergiermittel enthält, wobei unter Verwendung spezieller erfindungsgemäßer Dispergiermittel keramische Grünfolien mit überraschend vorteilhaften Eigenschaften erhalten werden können, die sich durch nachfolgende thermische Behandlung in isotrope keramische Substrate umwandeln lassen.The invention relates to the production of ceramic green films by casting and drying a slip which contains finely divided inorganic pigment, organic solvents, polyvinyl butyral, plasticizers and dispersants, ceramic green films having surprisingly advantageous properties which can be obtained by the following being obtained using special dispersants according to the invention Have thermal treatment converted into isotropic ceramic substrates.
Substrate aus keramischen Massen, beispielsweise aus Aluminiumoxid, können durch Gießen von sogenannten Schlickern hergestellt werden. Unter Schlicker wird dabei eine Aufschlämmung anorganischer Pigmente in einem organischen Lösungsmittel verstanden, welches ein polymeres Bindemittel, wie Polyvinylbutyral, und einen Weichmacher, wie z.B. einen Phthalsäureester, enthält. Dieser Schlicker wird auf ein kontinuierlich laufendes Metall- oder Kunststoffband gegossen, wobei eine konstante Schichtdicke der Gießmasse durch eine Rakel eingestellt wird. Auf dem Band wird der Schlicker getrocknet und es entsteht eine flexible Grünfolie, die sich kontinuierlich vom Band abziehen läßt. Die Grünfolie kann durch Schneiden und Stanzen leicht weiter verarbeitet werden. Anschließend werden die organischen Bestandteile durch ein spezielles Temperaturprogramm aus der Folie verdampft und diese schließlich bei hohen Temperaturen zum Substrat gesintert.Substrates made of ceramic materials, for example made of aluminum oxide, can be produced by casting so-called slip. Slurry is understood to mean a slurry of inorganic pigments in an organic solvent which contains a polymeric binder such as polyvinyl butyral and a plasticizer such as e.g. contains a phthalic acid ester. This slip is poured onto a continuously running metal or plastic belt, a constant layer thickness of the casting compound being set by means of a doctor blade. The slip is dried on the belt and a flexible green film is formed, which can be continuously removed from the belt. The green film can easily be processed further by cutting and punching. The organic components are then evaporated from the film using a special temperature program and finally sintered to the substrate at high temperatures.
Dieses wirtschaftliche Verfahren hat jedoch eine Reihe von Nachteilen, wovon hier nur wenige besonders schwerwiegende hervorgehoben werden sollen.However, this economic process has a number of disadvantages, only a few of which are particularly serious.
Nach dem Trocknen neigt die Grünfolie zum Kleben auf dem Band, speziell auf Metallband. Zum Abziehen vom Band ist soviel Kraft erforderlich, daß die Folie gedehnt wird. Es ist bekannt, das Band mit einem Gleitmittel zu behandeln, wodurch die Haftung der Folie - allerdings oft nicht ausreichend - erniedrigt wird.After drying, the green film tends to stick to the tape, especially on metal tape. To pull off the tape so much force is required that the film is stretched. It is known to treat the tape with a lubricant, which lowers the adhesion of the film, though often not sufficiently.
Beim Gießen des Schlickers tritt eine mehr oder weniger große Scherung auf. Dadurch werden nicht kugelförmige anorganische Teilchen, beispielsweise handelsübliches Aluminiumoxid, in Fließrichtung orientiert. Diese Orientierung wird noch verstärkt, wenn das organische Lösungsmittel/Bindemittel/Weichmachersystem als solches nicht homogen, sondern mehrphasig ist und wenn die Teilchengrößenverteilung der anorganischen Pigmente groß ist.When pouring the slip, a more or less high shear occurs. As a result, non-spherical inorganic particles, for example commercially available aluminum oxide, are oriented in the direction of flow. This orientation is reinforced if the organic solvent / binder / plasticizer system as such is not homogeneous, but rather multi-phase and if the particle size distribution of the inorganic pigments is large.
Alle geschilderten Effekte führen im allgemeinen dazu, daß beim Brennen und Sintern der Substrate längs und quer zur Fließrichtung unterschiedliche Schwindungen auftreten, die sich nicht reproduzierbar einstellen lassen.All of the effects described generally lead to different shrinkages occurring along and transversely to the direction of flow during firing and sintering of the substrates, which cannot be reproducibly adjusted.
Ein weiterer schwerwiegender Nachteil ist das Bestreben der anorganischen Teilchen, sich schon vor dem Trocknen in unkontrollierbarer Weise zusammen zu lagern. In den Teilchenaggregaten bilden sich kleine Hohlräume, d.h. die Teilchen sind nicht optimal dicht gepackt. Das verursacht wiederum eine hohe und schlecht reproduzierbare Schwindung der Grünfolien beim Brennen und es enstehen Anisotropien in dem resultierenden keramischen Substrat. Insgesamt führen die geschilderten Effekte dazu, daß es nicht möglich ist, Substrate mit präzisen Abmessungen durch das Gießverfahren herzustellen. Zur Herstellung von Präzisionsteilen ist es daher u.a. erforderlich, fertig gebrannte Substrate in aufwendigen Verfahren, beispielsweise mit Laserstrahlen, zu schneiden.Another serious disadvantage is the tendency of the inorganic particles to accumulate in an uncontrollable manner even before drying. Small voids form in the particle aggregates, i.e. the particles are not optimally packed. This in turn causes a high and poorly reproducible shrinkage of the green foils during firing and anisotropies arise in the resulting ceramic substrate. Overall, the effects described mean that it is not possible to produce substrates with precise dimensions using the casting process. For the production of precision parts, it is therefore among others required to cut finished substrates in complex processes, for example with laser beams.
Es hat bisher nicht an Versuchen gefehlt, das Problem der ungleichmäßigen Schwindung und der Bildung von Substratanisotropien zu verringern. Es setzte sich u.a. die Erkenntnis durch, daß es erforderlich ist, die anorganischen Teilchen besser zu dispergieren. So werden durch mehrtägiges Mahlen des Schlickers Teilchenaggregate zerstört, jedoch entstehen beim Gießen erneut nicht optimal dichte Aggregate. Günstiger ist es, Dispergiermittel wie Fischöl, Polyethylenglykole oder Ethylenoxid-Propylenoxid-Blockcopolymere zuzusetzen und als Bindemittel Polymere mit gut dispergierenden Eigenschaften, wie z.B. Polyvinylbutyral oder Acrylat-Copolymere, zu verwenden, wobei natürlich die Forderung erfüllt sein muß, daß sich die verwendeten organischen Verbindungen vollständig aus der Grünfolie entfernen lassen. Es konnten durch solche Maßnahmen merkliche Verbesserungen in der Dimensionierung der Substrate erreicht werden, so daß sich das Gießverfahren weltweit durchgesetzt hat. Trotzdem gelingt es immer noch nicht, nach dem Gießverfahren Substrate mit exakter Dimensionierung herzustellen. Das liegt einerseits daran, daß, wie z.B. bei der Verwendung von Fischöl oder anderen ungesättigten Fettsäureestern, zwar niedrigviskose Schlicker rasch herstellbar sind, die Primärteilchen aber nicht aggregatfrei gehalten werden können, oder daß die verwendeten Dispergiermittel mit dem Lösungsmittel, dem Bindemittel und dem Weichmacher keine homogene Phase bilden. Oft müssen auch die Zusätze in so hohen Konzentrationen verwendet werden, daß das Ausbrennen der organischen Bestandteile aus der Grünfolie erheblich behindert wird.There has been no lack of attempts to reduce the problem of uneven shrinkage and substrate anisotropy formation. Among other things, the Realization through that it is necessary to better disperse the inorganic particles. Particulate aggregates are destroyed by grinding the slurry for several days, however, aggregates that are not optimally dense again arise during casting. It is cheaper to add dispersants such as fish oil, polyethylene glycols or ethylene oxide-propylene oxide block copolymers and to use polymers with good dispersing properties, such as polyvinyl butyral or acrylate copolymers, as binders, although the requirement must of course be met that the organic compounds used completely remove from the green sheet. Such measures made it possible to achieve noticeable improvements in the dimensioning of the substrates, so that the casting process has become established worldwide. Nevertheless, it is still not possible to produce substrates with exact dimensions using the casting process. On the one hand, this is due to the fact that, for example when using fish oil or other unsaturated fatty acid esters, low-viscosity slurries can be produced quickly, but the primary particles cannot be kept free of aggregates, or that the dispersants used with the solvent, binder and plasticizer are none form homogeneous phase. The additives often have to be used in such high concentrations that the burning out of the organic constituents from the green sheet is considerably hindered.
Es wurde nun überraschenderweise gefunden, daß sich die genannten Nachteile überwinden lassen, wenn man in einem Bindemittelsystem, bestehend aus organischen Lösungsmitteln, Polyvinylbutyral, Weichmacher und Dispergiermittel, als Dispergiermittel Verbindungen einsetzt, die in ihren Molekülen mindestens eine Struktureinheit der Formel Z,
〉N-(A)x-(B)yH (Z)
worin A und B, die verschieden sein müssen, entweder für die Oxyalkyleneinheit -C₃₋₄H₆₋₈O- oder die Oxyalkyleneinheit -C₂H₄O- stehen und x und y, die gleich oder verschieden sein können, jeweils eine Zahl von 1 bis 200, vorzugsweise 2 bis 50, bedeuten, enthalten.It has now surprisingly been found that the disadvantages mentioned can be overcome if, in a binder system consisting of organic solvents, polyvinyl butyral, plasticizer and dispersant, compounds are used as dispersants which have at least one structural unit of the formula Z in their molecules,
〉 N- (A) x - (B) y H (Z)
wherein A and B, which must be different, are either the oxyalkylene unit -C₃₋₄H₆₋₈O- or the oxyalkylene unit -C₂H₄O- and x and y, which may be the same or different, each have a number from 1 to 200, preferably 2 to 50, mean contain.
Gegenstand der Erfindung ist daher ein Verfahren zur Herstellung von keramischen Grünfolien durch Vergießen und Trocknen eines Schlickers, der feinteiliges anorganisches Pigment, organische Lösungsmittel, Polyvinylbutyral, Weichmacher und Dispergiermittel enthält, dadurch gekennzeichnet, daß als Dispergiermittel Verbindungen eingesetzt werden, die in ihren Molekülen mindestens eine Struktureinheit der Formel Z,
〉N-(A)x-(B)yH (Z)
worin A und B, die verschieden sein müssen, entweder für die Oxyalkyleneinheit -C₃₋₄H₆₋₈O- oder die Oxyalkyleneinheit -C₂H₄O- stehen und x und y, die gleich oder verschieden sein können, jeweils eine Zahl von 1 bis 200, vorzugsweise 2 bis 50, bedeuten, enthalten.The invention therefore relates to a process for the production of ceramic green sheets by casting and drying a slip which contains finely divided inorganic pigment, organic solvents, polyvinyl butyral, plasticizers and dispersants, characterized in that compounds are used as dispersants which have at least one in their molecules Structural unit of formula Z,
〉 N- (A) x - (B) y H (Z)
wherein A and B, which must be different, are either the oxyalkylene unit -C₃₋₄H₆₋₈O- or the oxyalkylene unit -C₂H₄O- and x and y, which may be the same or different, each have a number from 1 to 200, preferably 2 to 50, mean contain.
Eine Ausführungsform der Erfindung besteht darin, daß die Struktureinheit der Formel Z den Formeln Z¹ oder Z²,
〉N-(C₂H₄O)x-(C₃H₆O)yH (Z¹)
〉N-(C₃H₆O)x-(C₂H₄O)yH (Z²)
worin x und y jeweils die Bedeutungen wie in Formel Z haben, entspricht.One embodiment of the invention consists in that the structural unit of the formula Z has the formulas Z 1 or Z 2,
〉 N- (C₂H₄O) x - (C₃H₆O) y H (Z¹)
〉 N- (C₃H₆O) x - (C₂H₄O) y H (Z²)
where x and y each have the meanings as in formula Z, corresponds.
Wie die der Grundformel Z entsprechenden Formeln Z¹ und Z² beispielhaft zeigen, stellen darin die Gruppen A und B die Oxyalkyleneinheiten -C₃H₆O- oder -C₂H₄O- dar, wobei A und B nicht gleich sind, d.h., die Gruppen A und B in Formel Z bilden zusammen stets blockcopolymere Strukturen bzw. stellen blockcopolymere Addukte dar.As the formulas Z¹ and Z² corresponding to the basic formula Z show by way of example, groups A and B therein represent the oxyalkylene units -C₃H₆O- or -C₂H₄O-, where A and B are not the same, ie groups A and B in formula Z together always form block-copolymer structures or represent block-copolymer adducts.
Eine bevorzugte Ausführungsform der Erfindung besteht darin, daß das erfindungsgemäße Dispergiermittel den Formeln I und/oder II,
worin x und y jeweils die Bedeutungen wie in Formel Z haben, entspricht.A preferred embodiment of the invention consists in that the dispersant according to the invention has the formulas I and / or II,
where x and y each have the meanings as in formula Z, corresponds.
Weiterer Gegenstand der Erfindung sind keramische Grünfolien, hergestellt durch Vergießen und Trocknen eines Schlickers, der feinteiliges anorganisches Pigment, organische Lösungsmittel, Polyvinylbutyral, Weichmacher und als Dispergiermittel Verbindungen enthält, die in ihren Molekülen mindestens eine Struktureinheit der Formel Z enthalten.The invention further relates to ceramic green sheets, produced by casting and drying a slip which contains finely divided inorganic pigment, organic solvents, polyvinyl butyral, plasticizers and, as dispersants, compounds which contain at least one structural unit of the formula Z in their molecules.
Weiterer Gegenstand der Erfindung ist ein keramisches Substrat, hergestellt aus erfindungsgemäß erhaltenen keramischen Grünfolien durch thermische Behandlung und Sinterung, vorzugsweise durch Erhitzen und Sintern bei Temperaturen von mindestens 1600°C, wobei es aus isotrop verteilten anorganischen Partikeln aufgebaut ist.The invention further relates to a ceramic substrate, produced from ceramic green foils obtained according to the invention by thermal treatment and sintering, preferably by heating and sintering at temperatures of at least 1600 ° C., it being composed of isotropically distributed inorganic particles.
Eine weitere Ausführungsform der Erfindung besteht darin, daß das erfindungsgemäße Dispergiermittel Verbindungen enthält, die durch Addition von einem oder mehreren blockcopolymer strukturierten Resten aus x Ethylenoxid-und y Propylenoxid-Einheiten oder x Propylenoxid- und y Ethylenoxid-Einheiten, wobei x und y in den blockcopolymer strukturierten Resten die Bedeutungen wie in Formel Z haben, an die Aminogruppen von primären oder sekundären Aminen, vorzugsweise aliphatischen Aminen, mit durch aliphatische (C₁-C₁₈)-Reste substituierten Amino-N-Atomen, bzw. von primären oder primären/sekundären oder sekundären Di- oder Polyaminen, vorzugsweise aliphatischen Di- oder Polyaminen mit durch aliphatische (C₁-C₁₈)-Reste substituierten Amino-N-Atomen oder durch mehrbindige aliphatische (C₁-C₁₂)-Reste miteinander verbundenen Amino-N-Atomen, insbesondere Di- oder Polyaminen mit 2 bis 4 primären und/oder sekundären Aminogruppen, wobei die genannten Amine bzw. Di- oder Polyamine zusätzlich auch tertiär oder quartär substituierte N-Atome und/oder weitere Substituenten enthalten können, darstellbar sind.A further embodiment of the invention is that the dispersant according to the invention contains compounds which, by adding one or more block copolymer structured residues of x ethylene oxide and y propylene oxide units or x propylene oxide and y ethylene oxide units, where x and y in the Block copolymer structured radicals have the meanings as in formula Z, to the amino groups of primary or secondary amines, preferably aliphatic amines, with amino-N atoms substituted by aliphatic (C₁-C₁₈) radicals, or of primary or primary / secondary or secondary di- or polyamines, preferably aliphatic di- or polyamines with amino-N atoms substituted by aliphatic (C₁-C₁₈) radicals or amino-N-atoms linked to one another by multi-bonded aliphatic (C₁-C₁₂) radicals, in particular di- or polyamines with 2 to 4 primary and / or secondary amino groups, the amines or diodes mentioned r Polyamines can also contain tertiary or quaternary substituted N atoms and / or further substituents.
Eine bevorzugte Ausführungsfrom der Erfindung besteht ferner darin, daß das erfindungsgemäße Dispergiermittel Verbindungen enthält, die durch Addition von vier blockcopolymer strukturierten Resten aus x Ethylenoxid-und y Propylenoxid-Einheiten oder x Propylenoxid- und y Ethylenoxid-Einheiten, wobei x und y in den blockcopolymer strukturierten Resten die Bedeutungen wie in Formel Z haben, an die Aminogruppen des Ethylendiamins darstellbar sind.A preferred embodiment of the invention further consists in the fact that the dispersant according to the invention contains compounds which, by adding four block copolymer structured residues of x ethylene oxide and y propylene oxide units or x propylene oxide and y ethylene oxide units, where x and y are in the block copolymer structured radicals have the meanings as in formula Z, on which amino groups of ethylenediamine can be represented.
Die erfindungsgemäßen Dispergiermittel haben eine gute bis hervorragende Dispergierwirkung. Die erfindungsgemäß dispergierten anorganischen Teilchen liegen im Schlicker als Primärteilchen vor, die auch beim Trocknen des Schlickers nicht vorzeitig aggregieren und die beim Gießen nicht oder nur wenig orientiert werden, so daß isotrope Grünfolien mit optimaler Dichte und damit optimaler Packungsdichte der anorganischen Teilchen erhalten werden.The dispersants of the invention have a good to excellent dispersing action. The inorganic particles dispersed according to the invention are present in the slip as primary particles, which do not aggregate prematurely even when the slip dries and which are not or only slightly oriented during casting, so that isotropic green films with optimum density and thus optimal packing density of the inorganic particles are obtained.
Im Gegensatz zu den meisten für die Herstellung keramischer Schlicker bekannten Dispergiermitteln sind die erfindungsgemäßen Verbindungen mit Polyvinylbutyral und den üblichen Lösungsmitteln und Weichmachern verträglich, so daß die pigmentfreie organische Phase völlig klare Filme ergibt.In contrast to most of the dispersing agents known for the production of ceramic slips, the compounds according to the invention are compatible with polyvinyl butyral and the customary solvents and plasticizers, so that the pigment-free organic phase results in completely clear films.
Ferner erniedrigen die erfindungsgemäßen Dispergiermittel die Haftung der Grünfolien auf dem Gießband, so daß beim Abziehen der Folien kein Verziehen oder Dehnen auftritt.Furthermore, the dispersants according to the invention reduce the adhesion of the green films to the casting belt, so that no warping or stretching occurs when the films are removed.
Auf Grund der geschilderten Eigenschaften gelingt es bei Verwendung der erfindungsgemäßen Dispergiermittel, Grünfolien herzustellen, die eine niedere Schwindung aufweisen bei ungewöhnlich geringer Differenz zwischen Längs- und Querschwindung. Dadurch gelingt es, durch das Gießverfahren Substrate mit ungewöhnlich genauer Dimensionierung reproduzierbar herzustellen.On the basis of the properties described, when using the dispersants according to the invention it is possible to produce green films which have a low shrinkage with an unusually small difference between the longitudinal and transverse shrinkage. This makes it possible to reproducibly produce substrates with unusually precise dimensions using the casting process.
Bei den erfindungsgemäß zu verwendenden Dispergiermitteln handelt es sich insbesondere um bekannte Verbindungen mit einer oder mehreren der Struktureinheiten
〉N-(C₂H₄O)x-(C₃H₆O)yH
und
〉N-(C₃H₆O)x-)C₂H₄O)yH,
worin x und y jeweils die Bedeutungen wie in Formel Z haben.The dispersants to be used according to the invention are in particular known compounds with one or more of the structural units
〉 N- (C₂H₄O) x - (C₃H₆O) y H
and
〉 N- (C₃H₆O) x -) C₂H₄O) y H,
where x and y each have the meanings as in formula Z.
Prinzipiell sind alle blockartigen bzw. blockcopolymeren Addukte von Propylenoxid und Ethylenoxid an beliebige primäre und/oder sekundäre Amine geeignet. Vorzuziehen sind jedoch die Addukte an primäre und sekundäre aliphatische Mono-, Di- und Polyamine, wie z.B. Ethyl-, Butyl-, Octyl-, Dodecyl-, Stearyl- und Oleylamin, Diethylamin, Methylstearylamin, Ethylendiamin, 1,6-Hexylendiamin, Diethylentriamin und Triethylentetramin.In principle, all block-like or block-copolymeric adducts of propylene oxide and ethylene oxide with any primary and / or secondary amines are suitable. However, the adducts with primary and secondary aliphatic mono-, di- and polyamines, such as e.g. Ethyl, butyl, octyl, dodecyl, stearyl and oleylamine, diethylamine, methylstearylamine, ethylenediamine, 1,6-hexylenediamine, diethylenetriamine and triethylenetetramine.
Besonders bevorzugt sind die Addukte an Ethylendiamin der Formel Z³,
worin A, B, x und y die Bedeutungen wie in Formel Z haben.The adducts of ethylenediamine of the formula Z3 are particularly preferred,
where A, B, x and y have the meanings as in formula Z.
Gegenüber der Herstellung von Keramikschlickern mit bekannten Dispergiermitteln haben die erfindungsgemäßen Dispergiermittel eine ganze Reihe von Vorteilen.
- 1. Sie haben eine sehr gute Dispergierwirkung und verhindern dadurch eine Agglomeration der anorganischen Pigmentprimärteilchen im Schlicker.
- 2. Sie sind vertraglich sowohl mit Polyvinylbutyral als auch mit den üblichen Weichmachern des Polyvinylbutyrals. In den homogenen Systemen Polyvinylbutyral/Weichmacher/Dispergiermittel haben sie daher eine zusätzlich weichmachende Wirkung, so daß die Konzentration an üblichem Weichmacher vermindert werden kann. Dies begünstigt wiederum das Trocknen der Grünfolie und das Ausheizen der organischen Bestandteile der Grünfolie.
- 3. Sie vermindern die Haftung der Grünfolie auf beliebigen Unterlagen.
- 4. Sie vermindern die Neigung zur Schaumbildung im Schlicker.
- 5. Sie ermöglichen die Verbesserung und Sicherstellung der Homogenität der Grünfolie.
- 6. Sie ermöglichen die kombinierte Verbesserung von Dispergier-, Antihaft- und Antischaumwirkung.
- 1. They have a very good dispersing action and thus prevent agglomeration of the inorganic pigment primary particles in the slip.
- 2. You are contracted both with polyvinyl butyral and with the usual plasticizers of polyvinyl butyral. In the homogeneous systems polyvinyl butyral / plasticizer / dispersant, they therefore have an additional plasticizing effect, so that the concentration of conventional plasticizer can be reduced. This in turn favors the drying of the green sheet and the heating of the organic components of the green sheet.
- 3. You reduce the liability of the green film on any documents.
- 4. You reduce the tendency to foam in the slip.
- 5. They make it possible to improve and ensure the homogeneity of the green film.
- 6. They enable the combined improvement of dispersing, non-stick and anti-foam effects.
Diese Kombination von Vorteilen mit einer einzigen Substanzklasse realisieren zu können, ist außerordentlich überraschend und war für den Fachmann nicht vorhersehbar. Die genannten Vorteile - Dispergierwirkung, Verträglichkeit, Antihaft- und Antischaumwirkung - sind bei den einzelnen Vertretern der erfindungsgemäß zu beanspruchenden Verbindungen unterschiedlich stark ausgeprägt. Im allgemeinen kann ganz grob die Regel angewandt werden, daß die beste Dispergierwirkung dann erreicht wird, wenn Oxypropylenblöcke außen am Molekül sitzen (B in obiger Formel Z³) und verhältnißmäßig groß sind. Umgekehrt haben Verbindungen mit außen am Molekül sitzenden Oxyethylenblöcken eine besonders gute Antihaft- und Antischaumwirkung. Es ist daher eine bevorzugte Ausführungsform der Erfindung, zwei oder mehr erfindungsgemäße Verbindungen mit unterschiedlich ausgeprägten Wirksamkeiten, beispielsweise Dispergier- und Antihaftwirkung, miteinander zu kombinieren.To be able to achieve this combination of advantages with a single class of substances is extremely surprising and was not foreseeable by the person skilled in the art. The advantages mentioned - dispersing action, compatibility, non-stick and anti-foaming action - are different in the individual representatives of the compounds to be claimed according to the invention. In general, the rule can be roughly applied that the best dispersing effect is achieved when oxypropylene blocks are on the outside of the molecule (B in the above formula Z 3) and are relatively large. Conversely, compounds with oxyethylene blocks on the outside of the molecule have a particularly good non-stick and anti-foam effect. It is therefore a preferred embodiment of the invention to combine two or more compounds according to the invention with different degrees of activity, for example dispersing and non-stick action.
Die Konzentration der erfindungsgemäß zu verwendenden Verbindungen kann in weiten Grenzen variieren. Prinzipiell ist es wünschenswert, so wenig Dispergiermittel wie möglich zu verwenden, um das Gießen und Trocknen des Schlickers nicht zu behindern. Andererseits ist es erforderlich, die anorganischen Teilchen vollstandig und optimal zu dispergieren, was wiederum von ihrer Art und ihrer Größe bzw. ihrer Oberfläche abhängt. Ähnliches gilt für die erforderliche Erniedrigung der Haftung der Grünfolie auf dem Gießband. Schließlich muß auch, wie erwähnt, auf die Verträglichkeit des gesamten Bindemittelsystems geachtet werden. Die optimale Konzentration an Dispergiermittel kann jedoch vom Fachmann an Hand der erwähnten Regeln und der unten beschriebenen Testmethoden ermittelt werden. Im allgemeinen werden die erfindungsgemäßen Dispergiermittel bzw. Dispergiermittelgemische in Konzentrationen zwischen 0,1 und 10 Gew.-%, bezogen auf das anorganische Pigment, verwendet. Ein bevorzugter Bereich liegt zwischen 0,2 und 5 Gew.-%. Besonders bevorzugt sind Konzentrationen zwischen 0,4 und 3 Gew.-%.The concentration of the compounds to be used according to the invention can vary within wide limits. In principle, it is desirable to use as little dispersant as possible so as not to impede the pouring and drying of the slip. On the other hand, it is necessary to completely and optimally disperse the inorganic particles, which in turn depends on their type and size or their surface. The same applies to the necessary lowering of the adhesion of the green film on the casting belt. Finally, as mentioned, attention must also be paid to the compatibility of the entire binder system will. However, the person skilled in the art can determine the optimum concentration of dispersant using the rules mentioned and the test methods described below. In general, the dispersants or dispersant mixtures according to the invention are used in concentrations between 0.1 and 10% by weight, based on the inorganic pigment. A preferred range is between 0.2 and 5% by weight. Concentrations between 0.4 and 3% by weight are particularly preferred.
Als Bindemittel können die handelsüblichen Polyvinylbutyrale verwendet werden. Diese Polyvinylbutyrale haben Viskositäten, gemessen an ihren 5 gew.-%igen Lösungen in Ethanol bei 23°C, zwischen 3 und 100 mPa·s. Vorzugsweise geeignet sind Polyvinylbutyrale oder auch Polyvinylbutyralgemische mit Viskositäten zwischen 5 und 20 mPa·s. Die handelsüblichen Polyvinylbutyrale sind Terpolymere, welche neben Vinylbutyraleinheiten ca. 0,5 bis 3 Gew.-% Vinylacetat- und 12 bis 28 Gew.-% Vinylalkoholeinheiten enthalten. Besonders die Vinylalkoholeinheiten haben einen wesentlichen Einfluß auf die Löslichkeit, die mechanischen und die rheologischen Eigenschaften der Polyvinylbutyrale. Bei der vorliegenden Anwendung sind die Verträglichkeit mit Weichmacher und Dispergiermittel einerseits und die mechanischen Eigenschaften andererseits von besonderer Bedeutung. Für eine optimale Einstellung dieser Eigenschaften sind Polyvinylbutyrale mit einem Gehalt an Vinylalkoholeinheiten zwischen 15 und 22 Gew.-% besonders bevorzugt.The commercially available polyvinyl butyrals can be used as binders. These polyvinyl butyrals have viscosities, measured on their 5% strength by weight solutions in ethanol at 23 ° C., between 3 and 100 mPa · s. Polyvinyl butyrals or else polyvinyl butyral mixtures with viscosities between 5 and 20 mPa · s are particularly suitable. The commercially available polyvinyl butyrals are terpolymers which, in addition to vinyl butyral units, contain about 0.5 to 3% by weight of vinyl acetate and 12 to 28% by weight of vinyl alcohol units. The vinyl alcohol units in particular have a significant influence on the solubility, the mechanical and the rheological properties of the polyvinyl butyrals. In the present application, the compatibility with plasticizer and dispersant on the one hand and the mechanical properties on the other hand are of particular importance. For optimal adjustment of these properties, polyvinyl butyrals with a vinyl alcohol unit content of between 15 and 22% by weight are particularly preferred.
Die Konzentration an Bindemittel hat einen wesentlichen Einfluß auf die Festigkeit und die Verarbeitbarkeit der Grünfolien. Folien mit zu wenig Bindemittel sind wenig fest und sind brüchig, zuviel Bindemittel erschwert das Ausheizen der organischen Bestandtiele aus der Grünfolie und kann zur Rißbildung im Substrat führen. Im allgemeinen werden Polyvinylbutyralkonzentrationen zwischen 2 und 10 Gew.-%, bezogen auf die anorganischen Pigmente, eingesetzt. Ein bevorzugter Bereich liegt zwischen 3 und 6 Gew.-%.The concentration of binder has a significant influence on the strength and processability of the green sheets. Films with too little binder are not very strong and are brittle, too much binder makes it difficult to heat the organic constituents out of the green film and can lead to cracking in the substrate. In general, polyvinyl butyral concentrations between 2 and 10 wt .-%, based on the inorganic pigments used. A preferred range is 3 to 6% by weight.
Bei der Herstellung von Grünfolien mit Polyvinylbutyral als Bindemittel kann auf die Anwesenheit eines Weichmachers nicht verzichtet werden. Weichmacherfreie Grünfolien sind zu wenig flexibel und sind brüchig.The presence of a plasticizer is indispensable in the production of green films with polyvinyl butyral as a binder. Plasticizer-free green films are not flexible enough and are brittle.
Das Verhältnis Weichmacher/Bindemittel bestimmt die Flexibilität der Folie. Zunehmende Weichmacherkonzentrationen verbessern die Dehnbarkeit der Folie, mit abnehmendem Weichmachergehalt nimmt die Festigkeit zu. Voraussetzung ist allerdings, daß es sich um ein homogenes, d.h. einphasiges Weichmacher/Bindemittelsystem handelt. Es sind prinzipiell alle Weichmacher geeignet, welche diese Forderung erfüllen, d.h. welche mit Polyvinylbutyral verträglich sind. Besonders geeignet sind beispielsweise Ester von Dicarbonsäuren, wie Phthalsäure, Adipinsäure und Sebazinsäure, mit aliphatischen oder aliphatisch-aromatischen Alkoholen, wie Dibutyl-, Dihexyl- oder Dioctylphthalat, Butylbenzylphthalat, Dioctyladipat oder Dibutylsebazat, ferner gegebenenfalls die entsprechenden Ester der Phosphorsäure. Weiterhin geeignet sind Ester von Monocarbonsäuren mit mehrwertigen Alkoholen, wie z.B. die Ester des Triethylenglykols mit aliphatischen Monocarbonsäuren mit 6 bis 8 Kohlenstoffatomen. Außerdem sind Ether langkettiger Alkohole geeignet, wie beispielsweise der Mono-isotridecylether des Triethylenglykols.The plasticizer / binder ratio determines the flexibility of the film. Increasing plasticizer concentrations improve the stretchability of the film, with decreasing plasticizer content the strength increases. However, the prerequisite is that it is a homogeneous, i.e. single-phase plasticizer / binder system. In principle, all plasticizers are suitable that meet this requirement, i.e. which are compatible with polyvinyl butyral. For example, esters of dicarboxylic acids, such as phthalic acid, adipic acid and sebacic acid, with aliphatic or aliphatic-aromatic alcohols, such as dibutyl, dihexyl or dioctyl phthalate, butylbenzyl phthalate, dioctyl adipate or dibutyl sebazate, and, if appropriate, the corresponding esters of phosphoric acid are particularly suitable. Esters of monocarboxylic acids with polyhydric alcohols, such as e.g. the esters of triethylene glycol with aliphatic monocarboxylic acids having 6 to 8 carbon atoms. In addition, ethers of long-chain alcohols are suitable, such as the mono-isotridecyl ether of triethylene glycol.
Da sie mit Polyvinylbutyral verträglich sind, wirken auch die erfindungsgemäß zu verwendenden Dispergiermittel prinzipiell als Weichmacher, welche geeignet sind, die Flexibilität der Grünfolien zu erhöhen. Aus diesem Grund kann auch das Dispergiermittel die oben erwähnten nicht dispergierenden Weichmacher zumindest teilweise ersetzen. Die Konzentration an nicht dispergierendem Weichmacher liegt daher zwischen 0 und 200 Gew.-% bezogen auf das eingesetzte Polyvinylbutyral. Ein bevorzugter Bereich liegt zwischen 10 und 150 Gew.-%, wobei die Obergrenze der Weichmacherkonzentration durch die beginnende Unverträglichkeit gesetzt wird.Since they are compatible with polyvinyl butyral, the dispersants to be used according to the invention also act in principle as plasticizers, which are suitable for increasing the flexibility of the green films. For this reason, the dispersant can at least partially replace the non-dispersing plasticizers mentioned above. The concentration of non-dispersing plasticizer is therefore between 0 and 200 wt .-% based on the Polyvinylbutyral used. A preferred range is between 10 and 150% by weight, the upper limit of the plasticizer concentration being set by the incompatibility that is beginning.
Für die Herstellung des Schlickers werden die üblichen Lösungsmittel verwendet. Es sind dies insbesondere Alkohole, wie Methanol und Ethanol, Halogenkohlenwasserstoffe wie Trichlorethylen, Ketone wie Methylethylketon oder Methylisobutylketon, aromatische Kohlenwasserstoffe wie Toluol oder Xylol. Häufig werden auch Gemische dieser Lösungsmittel verwendet.The usual solvents are used to produce the slip. These are in particular alcohols such as methanol and ethanol, halogenated hydrocarbons such as trichlorethylene, ketones such as methyl ethyl ketone or methyl isobutyl ketone, aromatic hydrocarbons such as toluene or xylene. Mixtures of these solvents are also frequently used.
Das Lösungsmittel beeinflußt in erster Linie die Viskosität des Schlickers und die Trocknungsgeschwindigkeit der Grünfolie. Die Konzentration des Lösungsmittels ist nicht kritisch und liegt innerhalb der üblichen Grenzen, vorzugsweise zwischen 20 und 100 Gew.-Teilen Lösungsmittel, insbesondere 30 bis 50 Gew.-Teilen, pro 100 Gew.-Teile anorganisches Pigment.The solvent primarily affects the viscosity of the slip and the drying speed of the green sheet. The concentration of the solvent is not critical and is within the usual limits, preferably between 20 and 100 parts by weight of solvent, in particular 30 to 50 parts by weight, per 100 parts by weight of inorganic pigment.
Prinzipiell können bei dem erfindungsgemäßen Verfahren sämtliche Pigmente verwendet werden, die sich für das Gießverfahren eignen. Sie können für den erfindungsgemäßen Verwendungszweck auf beliebige Weise hergestellt oder weiterverarbeitet worden sein, z.B. durch trockene oder nasse Mahlung. Für die Herstellung eines leicht dispergierbaren anorganischen Pigments kann es allerdings vorteilhaft sein, wenn z.B. nach einer Naßmahlung das Pigment in Gegenwart eines erfindungsgemäß zu verwendenden Dispergiermittels getrocknet wird.In principle, all pigments which are suitable for the casting process can be used in the process according to the invention. They can be manufactured or processed in any way for the intended use according to the invention, e.g. by dry or wet grinding. For the preparation of an easily dispersible inorganic pigment, however, it can be advantageous if, e.g. after wet grinding, the pigment is dried in the presence of a dispersant to be used according to the invention.
Wie schon erwähnt, sind viele feinteilige anorganische Pigmentpulver geeignet, wie z.B. die Oxide des Aluminiums, Magnesiums und Siliciums, Bariumtitanat, Silizium, Siliziumcarbid, Quarze, Alumosilikate, Gemische solcher Produkte und andere. Besonders eignen sich die erfindungsgemäß zu verwendenden Dispergiermittel bei der Herstellung von Substraten auf Basis Aluminiumoxid.As already mentioned, many finely divided inorganic pigment powders are suitable, such as, for example, the oxides of aluminum, magnesium and silicon, barium titanate, silicon, silicon carbide, quartz, aluminosilicates, mixtures of such products and others. They are particularly suitable Dispersant to be used according to the invention in the production of substrates based on aluminum oxide.
Neben den genannten Bestandteilen kann der Schlicker noch andere Zusätze enthalten, wie Verlaufmittel und Stabilisatoren, die wie die anderen im Schlicker enthaltenen organischen Verbindungen mit dem Bindemittelsystem verträglich sein sollten. Es ist aber auch möglich, andere organische Verarbeitungshilfsmittel einzusetzen, die mit der organischen Phase nicht verträglich sind und die feinteilig und inert in die Grünfolie eingelagert werden. Solche Zusätze, z.B. sogenannte Verflüssiger wie Fischöl oder andere Fettsäureester, können die Verflüssigung des Schlickers bei der Herstellung erleichtern. Sie dürfen aber die Kontinuität der Bindemittelphase nicht stören und die Dispergierwirkung der erfindungsgemäßen Verbindungen nicht beeinträchtigen. Ihre Konzentration, bezogen auf das eingesetzte Pigment, sollte daher gegebenenfalls 2 Gew.-%, vorzugsweise 1 Gew.-%, nicht überschreiten.In addition to the constituents mentioned, the slip can also contain other additives, such as leveling agents and stabilizers, which, like the other organic compounds contained in the slip, should be compatible with the binder system. However, it is also possible to use other organic processing aids which are incompatible with the organic phase and which are embedded in the green film in a finely divided and inert manner. Such additives, e.g. so-called liquefiers such as fish oil or other fatty acid esters can facilitate the liquefaction of the slip during manufacture. However, they must not disturb the continuity of the binder phase and must not impair the dispersing action of the compounds according to the invention. Their concentration, based on the pigment used, should therefore not exceed 2% by weight, preferably 1% by weight.
Die Herstellung und Verarbeitung der Schlicker erfolgt nach üblichen Methoden, z.B. durch Vermahlen des auf übliche Weise vorbehandelten und gegebenenfalls zerkleinerten Pigments in organischen Lösungsmitteln, wobei Bindemittel, Weichmacher, Dispergiermittel und andere Zusätze in beliebiger Reihenfolge zugegeben werden können. Vorzuziehen ist allerdings eine frühe Zugabe des Dispergiermittels und gegebenenfalls des Verflüssigers sowie eine relativ späte Zugabe des Bindemittels. Der fertige Schlicker wird mit Hilfe eines Gießschuhs und einer Rakel auf ein kontinuierlich laufendes Band aufgetragen, getrocknet und abgezogen. Anschließend kann die Grünfolie auf übliche Weise weiterverarbeitet werden. Beispielsweise kann die Aluminiumoxidgrünfolie zur Herstellung von Leiterbahnen, Isolatoren, Trägern für Siliziumchips, Trägern für elektronische Schaltkreise etc. verwendet werden.The slips are prepared and processed by customary methods, for example by grinding the pigment which has been pretreated in the customary manner and, if appropriate, comminuted in organic solvents, it being possible for binders, plasticizers, dispersants and other additives to be added in any order. However, it is preferable to add the dispersant and, if appropriate, the liquefier early, and to add the binder relatively late. The finished slip is applied with the help of a casting shoe and a doctor blade to a continuously running belt, dried and drawn off. The green film can then be processed further in the usual way. For example, the aluminum oxide green film can be used to produce conductor tracks, insulators, carriers for silicon chips, carriers for electronic circuits, etc.
Zur Charakterisierung des organischen Bindemittelsystems eignen sich verschiedene Testmethoden, die im folgenden unter A) bis G) beschrieben sind.Various test methods are suitable for characterizing the organic binder system and are described below under A) to G).
Die organischen Komponenten werden in der für die Schlickerherstellung vorgesehenen Zusammensetzung mit 0,2 mm Naßfilmdicke auf eine saubere Glasplatte aufgerakelt. Nach einer Trockenzeit von mindestens 24 Stunden bei Zimmertemperatur wird der Film bei ca. 200-facher Vergrößerung bei seitlicher Lichteinstrahlung unter dem Mikroskop betrachtet. Es darf (in Abwesenheit der oben als Verflüssiger erwähnten inerten Zusätze) keine Abscheidung einer zweiten Phase erkennbar sein. Wird der Film zu einer Schlaufe gefaltet und bei 23°C bei 100 % relativer Luftfeuchtigkeit 3 Tage gelagert, so sollte auf der Innenseite der Schlaufe keine Abscheidung erkennbar sein.The organic components are knife-coated onto the clean glass plate in the composition intended for slip production with a 0.2 mm wet film thickness. After a drying time of at least 24 hours at room temperature, the film is viewed under a microscope at approx. 200-fold magnification with lateral light. In the absence of the inert additives mentioned above as liquefiers, no separation of a second phase must be recognizable. If the film is folded into a loop and stored at 23 ° C at 100% relative humidity for 3 days, no separation should be discernible on the inside of the loop.
Das Dispergiervermögen eines Dispergiermittels wird ebenfalls in der organischen Lösung ermittelt, die für die Schlickerherstellung verwendet werden soll - allerdings in Abwesenheit des Bindemittels. In der organischen Lösung werden 0,1 Gew.-Teile Pigment mit einer mittleren Teilchengröße von ca. 0,5 µm und enger Korngrößenverteilung (z.B. Kronos Titandioxid RN 56) in 10 Gew.-Teilen Lösung in Gegenwart von Glasperlen 3 Stunden heftig geschüttelt. Je langsamer sich das dispergierte Pigment absetzt, um so besser ist die Dispergierwirkung. Die Dispergierwirkung ist befriedigend, wenn sich das Pigment nach 20 Stunden Stehen nur teilweise absetzt, sie ist gut, wenn sich in dieser Zeit nur eine geringe Menge des Pigments abgesetzt hat. Wird eine verdünnte Pigmentaufschlämmung unter dem Mikroskop betrachtet, nachdem sie in der beschriebenen Weise hergestellt worden ist, so dürfen keine oder nur wenige Pigmentaggregate erkennbar sein.The dispersing power of a dispersing agent is also determined in the organic solution that is to be used for the slip production - but in the absence of the binder. In the organic solution, 0.1 part by weight of pigment with an average particle size of approximately 0.5 μm and a narrow particle size distribution (for example Kronos titanium dioxide RN 56) in 10 parts by weight of solution in the presence of glass beads are shaken vigorously for 3 hours. The slower the dispersed pigment settles, the better the dispersing effect. The dispersing effect is satisfactory if the pigment only partially settles after standing for 20 hours; it is good if it is in has only deposited a small amount of the pigment during this time. If a diluted pigment slurry is viewed under the microscope after it has been produced in the manner described, no or only a few pigment aggregates must be recognizable.
Indirekt läßt sich eine gute Dispergierwirkung auch bei der Herstellung der Substrate feststellen. Enthalten zwei Grünfolien die gleichen anorganischen Bestandteile und die gleiche Menge unterschiedlicher Bindemittelsysteme, so hat die Folie mit besserer Dispergierung eine höhere Dichte und eine geringere Schwindung beim Sintern zum Substrat als die Folie mit weniger gut dispergierten anorganischen Teilchen.A good dispersing effect can also be found indirectly in the production of the substrates. If two green films contain the same inorganic components and the same amount of different binder systems, the film with better dispersion has a higher density and less shrinkage when sintered to the substrate than the film with less well-dispersed inorganic particles.
Wie bei der Überprüfung der Homogenität (Testmethode A) wird ein Film auf eine saubere Glasplatte (Objektträger) aufgerakelt und 24 Stunden getrocknet. Die Haftung ist "sehr gering", wenn sich der Film mit einer Pinzette von einem Objektträger, der eine Abmessung von ca. 25x76x1 mm aufweist und mit seiner Rückseite lose auf einer Unterlage aufliegt, abziehen läßt, ohne daß der Objektträger angefaßt werden muß. "Gering" ist die Haftung, wenn das Abziehen eines 6 cm breiten Films von einer Glasplatte mit der Abmessung 100x300x3 mm in entsprechender Weise gelingt. "Maßig" ist die Haftung, wenn beim Abziehen die Glasplatte angefaßt werden muß, der Film dabei aber nicht stark gedehnt wird. "Hoch" ist die Haftung, wenn der Film gedehnt wird und "sehr hoch", wenn sich der Film nicht unbeschädigt abziehen läßt.As with checking the homogeneity (test method A), a film is knife-coated onto a clean glass plate (slide) and dried for 24 hours. Adhesion is "very low" if the film can be removed with tweezers from a slide with a dimension of approx. 25x76x1 mm and with its back lying loosely on a surface without having to touch the slide. The liability is "low" if a 6 cm wide film can be pulled off from a glass plate with the dimensions 100x300x3 mm in a corresponding manner. Adhesion is "moderate" if the glass plate has to be touched when pulling it off, but the film is not stretched too much. The liability is "high" if the film is stretched and "very high" if the film cannot be removed undamaged.
Wird eine Grünfolie mit 200 µm Naßfilmdicke auf eine saubere Glasplatte aufgerakelt, so läßt sie sich nach dem Trocknen "leicht" abziehen, wenn dies mühelos gelingt, ohne daß die Folie an irgendeiner Stelle einreißt.If a green film with a wet film thickness of 200 µm is knife-coated onto a clean glass plate, it can be "easily" removed after drying if this can be done effortlessly without the film tearing at any point.
Die Viskositätsmessung des Schlickers oder der organischen Lösungen kann mit üblichen Viskosimetern des Systems Höppler oder des Systems Brookfield vorgenommen werden.The viscosity measurement of the slip or of the organic solutions can be carried out using conventional viscometers from the Höppler system or the Brookfield system.
Auch die Prüfung von Zugfestigkeit und Zugdehnung von pigmentfreien Folien und von Grünfolien kann mit handelsüblichen Maschinen vorgenommen werden. Zur Ausprüfung der Grünfolien wurde eine Maschine vom Typ Instron verwendet. Folienstreifen mit 0,5 bis 0,8 mm Dicke und 15 mm Breite wurden bei einer Einspannlänge von 50 mm mit einer Geschwindigkeit von 5 mm/min gerissen.The tensile strength and tensile elongation of pigment-free films and green films can also be checked using commercially available machines. An Instron machine was used to check the green sheets. Film strips with a thickness of 0.5 to 0.8 mm and a width of 15 mm were torn at a clamping length of 50 mm at a speed of 5 mm / min.
An pigmentfreien Folien oder an Filmen, die nur wenig, z.B. nicht mehr als 1 Gew.-%, Pigment enthalten, läßt sich eine Orientierung makroskopisch oder mikroskopisch durch Streifenbildung, Ausrichtung der Pigmente oder Bildung von in Gießrichtung ausgerichteten Strukturen erkennen. Bei Grünfolien ist eine entsprechende Untersuchung nicht aussagekräftig. An diesen Folien läßt sich die Orientierung am besten an der unterschiedlichen Schwindung längs und quer zur Gießrichtung beim Brennen der Grünfolie und Sintern zum Substrat erkennen.On pigment-free films or on films that are only slightly, e.g. no more than 1% by weight of pigment, orientation can be recognized macroscopically or microscopically by streaking, alignment of the pigments or formation of structures aligned in the casting direction. A corresponding examination is not meaningful for green foils. The orientation of these foils can best be seen from the different shrinkage along and across the casting direction when the green foil is fired and sintered to the substrate.
Die Neigung zur Schaumbildung im organischen Bindemittelsystem läßt sich am besten in Abwesenheit von anorganischen Pigmenten ermitteln. Es wird dabei eine Probe definiert geschüttelt und das Zusammenfallen des an der Oberfläche gebildeten Schaums im Vergleich zu einer Standardprobe beobachtet.The tendency to foam in the organic binder system can best be determined in the absence of inorganic pigments. A sample is shaken in a defined manner and the collapse of the foam formed on the surface is observed in comparison to a standard sample.
Die Erfindung wird durch die nachfolgenden Beispiele näher erläutert.The invention is illustrated by the following examples.
Es wurde eine Lösung aus 10 Gew.-Teilen Polyvinylbutyral, 61,5 Gew.-Teilen Trichlorethylen, 25 Gew.-Teilen wasserfreiem Ethanol und 3,5 Gew.-Teilen Bis-2-ethylhexylphthalat (DOP) hergestellt. Das verwendete Polyvinylbutyral hatte einen Gehalt an Vinylalkoholeinheiten von 18 Gew.-% und eine Viskosität von 12 mPa·s, gemessen an einer 5 gew.-%igen Lösung in Ethanol bei 23°C. Zu jeweils 10 g dieser Lösung wurden jeweils 0,15 g eines der in Tabelle 1 angegebenen Dispergiermittel der Substanzklassen der Formel I bzw. II (= Dispergiermittel a) bzw. b)), worin x und y die in Tabelle 1 angegebenen Zahlen bedeuten, zugesetzt. In Fläschchen wurden die Lösungen 5 Minuten heftig geschüttelt und die Schaumbildung,wie vorstehend unter Testmethode G) beschrieben, beurteilt. Außerdem wurden die Lösungen mit 200 µm Naßfilmdicke auf Glasplatten aufgerakelt. Die getrockneten Filme wurden unter dem Mikroskop, wie vorstehend unter Testmethode A) beschrieben, auf Homogenität geprüft. Die Versuchsergebnisse sind der folgenden Tabelle 1 zu entnehmen.
Beispiel 1 wurde wiederholt mit der Abänderung, daß anstelle der erfindungsgemäßen Dispergiermittel a) bzw. b) die in Tabelle 1a) angegebenen üblichen Zusatzmittel eingesetzt wurden. Die Prüfungen erfolgten analog Beispiel 1. Die Versuchsergebnisse sind der folgenden Tabelle 1a) zu entnehmen.
Das Beispiel 1 zeigt, daß die erfindungsgemäßen Dispergiermittel mit Polyvinylbutyral und Weichmacher verträglich sind und wenig Schaumbildung hervorrufen, während die bekannten Zusatzmittel gemäß Vergleichsbeispiel 1 zu Nachteilen führen.Example 1 shows that the dispersants according to the invention are compatible with polyvinyl butyral and plasticizers and cause little foaming, while the known additives according to Comparative Example 1 lead to disadvantages.
Es wurden jeweils 0,1 Gew.-Teile des Pigments Kronos Titandioxid RN 56 wie vorstehend unter Testmethode B) angegeben in jeweils 10 Gew.-Teilen einer Lösung aus 68 Gew.-Teilen Trichlorethylen, 27,5 Gew.-Teilen wasserfreiem Ethanol und 4,5 Gew.-Teilen DOP dispergiert, wobei zu jeweils 10 Gew.-Teilen der Lösung die in Tabelle 2 angegebenen unterschiedlichen Mengen der in Tabelle 2 ebenfalls genannten Dispergiermittel zugesetzt wurden. Als Dispergiermittel wurden die in Beispiel 1 beschriebenen erfindungsgemäßen Dispergiermittel a) (= Dispergiermittel der Formel I) bzw. b) (= Dispergiermittel der Formel II) verwendet, wobei x und y in Formeln I und II die in Tabelle 2 angegebenen Zahlen bedeuten. Die Dispergierwirkung wurde aus Absetzgeschwindigkeit und Beobachtung der Aggregatbildung, wie vorstehend unter Testmethode B) angegeben, beurteilt. Die Versuchsergebnisse sind der folgenden Tabelle 2 zu entnehmen.
Beispiel 2 wurde wiederholt mit der Abänderung, daß anstelle der erfindungsgemäßen Dispergiermittel a) bzw. b) die in Tabelle 2a) angegebenen und zur Beeinflussung der Dispergierung üblichen Zusatzmittel eingesetzt wurden. Die Prüfungen erfolgten analog Beispiel 2. Die Versuchsergebnisse sind der folgenden Tabelle 2a) zu entnehmen.
Das Beispiel 2 zeigt, daß die erfindungsgemäßen Dispergiermittel, vergleichsweise zu üblichen Dispergiermitteln auf der Basis von Ethylenoxid- bzw. Propylenoxidaddukten des Vergleichsbeispiels 2, eine überlegene Dispergierwirkung besitzen.Example 2 shows that the dispersants of the invention, compared to conventional dispersants based on ethylene oxide or propylene oxide adducts from Comparative Example 2, have a superior dispersing action.
Aus 10 Gew.-Teilen Polyvinylbutyral, 60,5 Gew.-Teilen Trichlorethylen, 24,5 Gew.-Teilen wasserfreiem Ethanol, 1,0 Gew.-Teilen Methoxypropylacetat und 4,0 Gew.-Teilen Dibutylphthalat wurde eine Lösung hergestellt. Das verwendete Polyvinylbutyral hatte einen Anteil von 19,2 Gew.-% Vinylalkoholeinheiten und eine Viskosität von 9,5 mPa·s, gemessen in 5 gew.-%iger Lösung in Ethanol bei 23°C. Zu jeweils 10 g dieser Lösung wurden jeweils 0,1 g eines der in Tabelle 1 angegebenen Dispergiermittel a) bzw. b) der Substanzklassen der Formel I bzw. II (= Dispergiermittel a) bzw. b)), worin x und y die in Tabelle 3 angegebenen Zahlen bedeuten, oder eine Kombination der Dispergiermittel a) und b) zugesetzt. Von den resultierenden Lösungen wurden, wie in Beispiel 1 angegeben, Filme hergestellt. Die Haftung dieser Filme auf Glas wurde, wie vorstehend unter Testmethode C) beschrieben, ermittelt. Die Ergebnisse dieser Versuche sind der folgenden Tabelle 3 zu entnehmen.
Beispiel 3 wurde wiederholt mit der Abänderung, daß anstelle der erfindungsgemäßen Dispergiermittel a) bzw. b) die in Tabelle 3a) angegebenen und zur Beeinflussung der Dispergierung üblichen Zusatzmittel eingesetzt wurden. Die Prüfungen erfolgten analog Beispiel 3. Die Versuchsergebnisse sind der folgenden Tabelle 3a) zu entnehmen.
Das Beispiel 3 demonstriert die haftungserniedrigende Wirkung erfindungsgemäßer Dispergiermittel gegenüber üblicherweise als Dispergiermittel eingesetzten Vergleichssubstanzen des Vergleichsbeispiels 3.Example 3 demonstrates the adhesion-reducing effect of dispersants according to the invention compared to comparison substances of comparative example 3 which are usually used as dispersants.
Es wurde eine Lösung von 4,5 Gew.-Teilen Polyvinylbutyral (Zusammensetzung wie in Beispiel 3), 0,5 Gew.-Teilen Menhaden-Fischöl, 1,7 Gew.-Teilen Dioctylphthalat und 2,3 Gew.-Teilen Dibutylphthalat in 30 Gew.-Teilen Toluol und 10 Gew.-Teilen wasserfreiem Ethanol hergestellt. Die Lösung wurde mit 200 µm Naßfilmdicke auf eine Glasplatte aufgerakelt. Der getrocknete Film haftete sehr stark auf der Glasplatte. Wurden dagegen derselben Lösung 0,8 Gew.-Teile des erfindungsgemäßen Dispergiermittels a) der Formel I mit x = 30 und y = 4 (vgl. Tabelle 1) zugesetzt, so war die Haftung eines auf dieselbe Weise hergestellten Films auf Glas gering.A solution of 4.5 parts by weight of polyvinyl butyral (composition as in Example 3), 0.5 part by weight of Menhaden fish oil, 1.7 parts by weight of dioctyl phthalate and 2.3 parts by weight of dibutyl phthalate was added 30 parts by weight of toluene and 10 parts by weight of anhydrous ethanol. The solution was knife-coated onto a glass plate with a wet film thickness of 200 μm. The dried film adhered very strongly to the glass plate. In contrast, if 0.8 part by weight of the dispersant a) of the formula I with x = 30 and y = 4 (cf. Table 1) were added to the same solution, the adhesion of a film produced in the same way to glass was poor.
Es wurden zwei Polymerlösungen jeweils aus Polyvinylbutyral, Trichlorethylen, Ethanol und Dioctylphthalat wie in Beispiel 1 beschrieben hergestellt. Eine der Lösungen wurde entsprechend dem Stand der Technik mit 1,7 Gew.-% (bezogen auf die Lösung) eines statistischen Copolymeren aus Ethylenoxid und Propylenoxid mit dem Molekulargewicht 3200 sowie mit 2,5 Gew.-% eines Fettsäureesters (Loxiol G 70 der Firma Henkel) versetzt (= Versuch 1). Der zweiten Lösung wurde das in Tabelle 1 beschriebene erfindungsgemäße Dispergiermittel b) der Formel II mit x = 15 und y = 7,5 zugesetzt (= Versuch 2). Zu beiden Lösungen wurden außerdem 3 Gew.-% feinteiliges Aluminiumoxid zugegeben, welches durch Versprühen aus wäßriger Aufschlämmung getrocknet worden war. Beide Lösungen wurden 20 Stunden in einer Kugelmühle gemahlen.Two polymer solutions were each prepared from polyvinyl butyral, trichlorethylene, ethanol and dioctyl phthalate as described in Example 1. One of the solutions was prepared according to the prior art with 1.7 wt .-% (based on the solution) of a random copolymer of ethylene oxide and propylene oxide with a molecular weight of 3200 and with 2.5 wt .-% of a fatty acid ester (Loxiol G 70 der Henkel) offset (= experiment 1). The inventive dispersant b) of the formula II with x = 15 and y = 7.5 was added to the second solution (= test 2). In addition, 3% by weight of finely divided aluminum oxide, which had been dried by spraying from an aqueous slurry, was added to both solutions. Both solutions were ball milled for 20 hours.
Schließlich wurden mit 50 µm Naßfilmdicke Filme auf Glas aufgezogen und bei 200-facher Vergrößerung unter dem Mikroskop betrachtet. FIGUR 1 zeigt einen Film nach dem Stand der Technik (= Versuch 1) mit stark inhomogener Verteilung der Aluminiumoxidpartikel in dem Bindemittelfilm. Der erfindungsgemäß hergestellte Film (= Versuch 2) demonstriert, wie die FIGUR 2 zeigt, die überlegene Dispergierwirkung erfindungsgemäßer Dispergiermittel, da er eine völlig homogene Verteilung der Aluminiumoxidpartikel in dem Bindemittelfilm aufweist.Finally, films were drawn onto glass with a wet film thickness of 50 μm and viewed under a microscope at a magnification of 200 times. FIGURE 1 shows a film according to the prior art (= test 1) with a strongly inhomogeneous distribution of the aluminum oxide particles in the binder film. The film produced according to the invention (= experiment 2) demonstrates, as FIGURE 2 shows, the superior dispersing effect of dispersing agents according to the invention, since it has a completely homogeneous distribution of the aluminum oxide particles in the binder film.
100 Gew.-Teile Aluminiumoxid mit einer mittleren Teilchengröße von 2 µm wurden in 24 Gew.-Teilen Trichlorethylen, 10 Gew.-Teilen wasserfreiem Ethanol und 0,8 Gew.-Teilen des in Tabelle 1 beschriebenen erfindungsgemäßen Dispergiermittels b) der Formel II mit x = 15 und y = 7,5 20 Stunden in einer Kugelmühle gemahlen. Anschließend wurden 4 Teile Polyvinylbutyral der Spezifikation wie in Beispiel 1 beschrieben und 1,5 Teile Dioctylphthalat zugesetzt und das Gemisch noch weitere 6 Stunden gemahlen. Der resultierende Schlicker wurde auf eine Glasplatte gegossen und getrocknet, wobei eine flexible Grünfolie mit einer Dicke von 0,6 mm entstand. Die Folie konnte leicht von der Glasplatte abgezogen werden. Nach 3 Tagen Lagerung bei 23°C und 50 % relativer Feuchte hatte die Folie eine Reißfestigkeit von 2,1 N/mm² bei einer Reißdehnung von 10,5 %. Wurde bei dieser Rezeptur anstelle des erfindungsgemäßen Dispergiermittels b) der Formel II Menhaden-Fischöl verwendet, so ließ sich die resultierende Folie nur sehr schwer vom Glas abziehen. Bei einer Reißfestigkeit von ebenfalls 2,1 N/mm² hatte sie außerdem lediglich eine Reißdehnung von 7,6 %.100 parts by weight of aluminum oxide with an average particle size of 2 .mu.m were mixed in 24 parts by weight of trichlorethylene, 10 parts by weight of anhydrous ethanol and 0.8 part by weight of the dispersant b) of the formula II described in Table 1 x = 15 and y = 7.5 milled in a ball mill for 20 hours. Then 4 parts of polyvinyl butyral of the specification as described in Example 1 and 1.5 parts of dioctyl phthalate were added and the mixture was ground for a further 6 hours. The resulting slurry was poured onto a glass plate and dried, forming a flexible green sheet with a thickness of 0.6 mm. The film could easily be pulled off the glass plate. After 3 days of storage at 23 ° C. and 50% relative humidity, the film had a tear strength of 2.1 N / mm² and an elongation at break of 10.5%. If Menhaden fish oil was used in this formulation instead of the dispersant b) of the formula II according to the invention, the resulting film was very difficult to remove from the glass. With a tensile strength of 2.1 N / mm², it also had an elongation at break of only 7.6%.
Durch Gießen auf ein Metallband nach üblichem Verfahren wurde eine Grünfolie hergestellt, die aus 100 Gew.-Teilen Aluminiumoxid (mittlere Teilchengröße 2 µm), 3,8 Gew.-Teilen Polyvinylbutyral (Spezifikation wie in Beispiel 3 beschrieben), 1,5 Gew.-Teilen DOP, 0,4 Gew.-Teilen des erfindungsgemäßen Dispergiermittels a) der Formel I mit x = 30 und y = 4, und 1,0 Gew.-Teilen des erfindungsgemäßen Dispergiermittels b) der Formel II mit x = 15 und y = 7,5 (vgl. Tabelle 1) bestand. Die Folie ließ sich leicht vom Band abziehen. Aus der Grünfolie wurde durch Brennen bei 1600°C ein Substrat hergestellt. Die dabei auftretende Schwindung lag längs zur Gießrichtung bei 17,1 % und quer zur Gießrichtung bei 17,0 %. Wurden die verwendeten erfindungsgemäßen Dispergiermittel a) und b) der Formeln I und II durch 0,4 Gew.-Teile Menhaden-Fischöl und 1,0 Gew.-Teile eines statistischen Ethylenoxid-Propylenoxid Copolymerisats mit einem Molekulargewicht von 4000 ersetzt, so haftete die dabei resultierende Folie deutlich stärker auf dem Gießband. Die Schwindung beim Brennen zum Substrat lag bei 19,2 % (längs) und bei 18,1 % (quer). Die geringere, einheitlichere und weitgehend isotrope Schwindung der nach dem erfindungsgemäßen Verfahren hergestellten Folie demonstriert die bessere Dispergierung gegenüber dem Vergleichsversuch gemäß dem Stand der Technik.A green film was produced by casting on a metal strip according to the customary method, and was made from 100 parts by weight of aluminum oxide (average particle size 2 μm), 3.8 parts by weight of polyvinyl butyral (specification as described in Example 3), and 1.5 parts by weight. Parts of DOP, 0.4 part by weight of the dispersant a) of the formula I according to the invention with x = 30 and y = 4, and 1.0 part by weight of the dispersant b) of the formula II according to the invention with x = 15 and y = 7.5 (see Table 1). The film was easy to pull off the tape. A substrate was produced from the green sheet by firing at 1600 ° C. The shrinkage that occurred was 17.1% in the longitudinal direction and 17.0% in the transverse direction. If the dispersants a) and b) of the formulas I and II used according to the invention were replaced by 0.4 part by weight of menhaden fish oil and 1.0 part by weight of a random ethylene oxide-propylene oxide copolymer with a molecular weight of 4000, the adhesive adhered the resulting film is much stronger on the casting belt. The shrinkage when burning to the substrate was 19.2% (lengthways) and 18.1% (lengthways). The lower, more uniform and largely isotropic shrinkage of the film produced by the process according to the invention demonstrates the better dispersion compared to the comparative test according to the prior art.
Claims (10)
- A process for the production of a ceramic green films by casting and drying a slip containing finely divided inorganic pigment, organic solvents, polyvinylbutyral, plasticizer and dispersing agent, which comprises using compounds which contain in their molecules at least one structural unit of the formula Z
〉N-(A)x-(B)yH (Z)
in which A and B, which must be different, stand for either the oxyalkylene unit -C₃₋₄H₆₋₈O- or the oxyalkylene unit -C₂H₄O- and x and y, which can be identical or different, each denote a number from 1 to 200, as dispersing agents. - An embodiment as claimed in claim 1, wherein the structural unit of the formula Z corresponds to the formula Z¹ or Z²
〉N-(C₂H₄O)x₋(C₃H₆O)yH (Z¹)
〉N-(C₃H₆O)x-(C₂H₄O)yH (Z²)
in which x and y in each case have the meanings as in formula Z. - An embodiment as claimed in either of claims 1 and 2, wherein the dispersing agent contains compounds which can be prepared by addition of one or more radicals of block copolymer structure of x ethylene oxide units and y propylene oxide units or x propylene oxide units and y ethylene oxide units, x and y in the radicals of block copolymer structure having the meanings as in formula Z, onto the amino groups of primary or secondary amines, having amino-N atoms substituted by aliphatic (C₁-C₁₈)-radicals, or of primary or primary/secondary or secondary di- or polyamines, having amino-N atoms substituted by aliphatic (C₁-C₁₈)-radicals or amino-N atoms bonded to one another by multivalent aliphatic (C₁-C₁₂)-radicals, it also being possible for the amines or di- or polyamines mentioned additionally to contain tertiary- or quaternary-substituted N atoms and/or other substituents.
- An embodiment as claimed in any one of claims 1 to 3, wherein the dispersing agent contains compounds which can be prepared by addition of four radicals of block copolymer structure of x ethylene oxide units and y propylene oxide units or x propylene oxide units and y ethylene oxide units, x and y in the radicals of block copolymer structure having the meanings as in formula Z, onto the amino groups of ethylenediamine.
- An embodiment as claimed in any one of claims 1 to 4, wherein the dispersing agent is used in an amount of 0.1 to 10% by weight, based on the inorganic pigment.
- An embodiment as claimed in any one of claims 1 to 5, wherein finely divided aluminum oxide is used as the inorganic pigment.
- An embodiment as claimed in any one of claims 1 to 6, wherein the polyvinylbutyral used contains between 15 and 22% by weight of vinyl alcohol units.
- The use of a dispersing agent as claimed in any one of claims 1 to 7 for the production of a ceramic slip, casting and drying of the slip to give a ceramic green film and subsequent conversion of the green film by heat treatment and sintering into a ceramic substrate.
- A ceramic green film produced as claimed in any one of claims 1 to 8.
- A ceramic substrate produced as claimed in claim 8 from a ceramic green film as claimed in claim 9, which is constituted by inorganic particles of isotropic distribution.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT88119004T ATE85315T1 (en) | 1988-11-15 | 1988-11-15 | PROCESS FOR THE MANUFACTURE OF CERAMIC GREEN FILMS. |
| EP88119004A EP0369045B1 (en) | 1988-11-15 | 1988-11-15 | Process for the production of ceramic green sheets |
| DE8888119004T DE3878249D1 (en) | 1988-11-15 | 1988-11-15 | METHOD FOR PRODUCING CERAMIC GREEN FILMS. |
| US07/281,200 US4968473A (en) | 1988-11-15 | 1988-12-07 | Process for the production of ceramic green films |
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| EP88119004A EP0369045B1 (en) | 1988-11-15 | 1988-11-15 | Process for the production of ceramic green sheets |
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| EP0369045A1 EP0369045A1 (en) | 1990-05-23 |
| EP0369045B1 true EP0369045B1 (en) | 1993-02-03 |
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| US (1) | US4968473A (en) |
| EP (1) | EP0369045B1 (en) |
| AT (1) | ATE85315T1 (en) |
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|---|---|---|---|---|
| DE4026965A1 (en) * | 1990-08-25 | 1992-02-27 | Basf Ag | CUSHIONABLE POWDER CONTAINING POWLABLE MOLD |
| EP0517390B1 (en) * | 1991-06-07 | 1996-09-04 | Nalco Chemical Company | Method and compositions for binding ceramic powders |
| EP0671371A1 (en) * | 1994-02-14 | 1995-09-13 | Rohm And Haas Company | Low foaming ceramic slip |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2966719A (en) * | 1954-06-15 | 1961-01-03 | American Lava Corp | Manufacture of ceramics |
| JPS5817143B2 (en) * | 1979-02-22 | 1983-04-05 | 鳴海製陶株式会社 | Ceramic tape manufacturing method |
| GB8402801D0 (en) * | 1984-02-02 | 1984-03-07 | Ici Plc | Dispersion |
| JPS6112306A (en) * | 1984-06-25 | 1986-01-20 | インタ−ナショナル ビジネス マシ−ンズ コ−ポレ−ション | Method of forming slurry for pour-molding for ceramic-sheet |
| DE3724108A1 (en) * | 1987-07-21 | 1989-02-02 | Hoechst Ag | Process for producing ceramic green sheets |
-
1988
- 1988-11-15 AT AT88119004T patent/ATE85315T1/en not_active IP Right Cessation
- 1988-11-15 DE DE8888119004T patent/DE3878249D1/en not_active Expired - Fee Related
- 1988-11-15 EP EP88119004A patent/EP0369045B1/en not_active Expired - Lifetime
- 1988-12-07 US US07/281,200 patent/US4968473A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| ATE85315T1 (en) | 1993-02-15 |
| EP0369045A1 (en) | 1990-05-23 |
| DE3878249D1 (en) | 1993-03-18 |
| US4968473A (en) | 1990-11-06 |
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